Fred,
same thing happened to me with my 1971 TR6. It had bad gas sitting for too long and actually broke 3-rocker arms because of stuck valves.
I sent everything off to rocker arms unlimited because they are the best and were also the lowest priced. They have been around forever.
Also if you have your head shaved for higher compression, I did for 9.25 compression ratio, you'll also need to get shorter push rods.
The best place for them is Smith Bros.(www.pushrods.net) Been around since 1953.
Not only is it an upgraded push rod but they are about $110 less than at Moss. I paid $86 for a set.
All you have to do is give them the dimension needed.

Also Fred, your in the middle of Nascar country. You will have some of the best machine shops around.
Call, Flying Circus English Cars, in Durham. 919-596-4250. Been around for a long time and they can help and direct you.